A high-temperature fiber product and its preparation method

Abstract

The application discloses a high-temperature fiber product and a preparation method thereof, and relates to the technical field of high-temperature fiber products.The high-temperature fiber product is prepared by preparing a mullite crystal fiber with Al2O3 being greater than or equal to 80%, a filler and a loss on ignition, weighing the above raw materials according to a proportioning ratio, mixing the raw materials uniformly in a planetary mixer, adding a binding agent to the mixed raw materials to form semi-dry materials, adding the semi-dry materials into a mold, forming the semi-dry materials into a green body through vibration and pressure, taking out the green body from the mold and drying the green body, and calcining the dried green body in a high-temperature kiln, wherein the calcining temperature is 1500 DEG C to 1600 DEG C, and the calcining temperature is kept for 4 to 6 hours.The high-temperature fiber product prepared by the preparation method has a bulk density of 0.5 to 0.8 g / cm 3 , a normal-temperature compressive strength of 1.0 to 3.0 Mpa, and a service temperature of 1650 DEG C to 1700 DEG C.The product can be used as a heat-insulating material or a furnace lining material, and the semi-dry forming process is simple in process, low in energy consumption and low in manufacturing cost.

Description

Technical Field

[0001] This invention relates to the technical field of high-temperature fiber products, and in particular to a high-temperature fiber product and its preparation method. Background Technology

[0002] As is well known, refractory fiber materials are lightweight materials that are both heat-resistant and have excellent thermal insulation properties. They are widely used in industrial furnaces, high-temperature conveying, fire protection, electronic equipment and other fields. Traditional refractory fiber products are mostly made using wet molding processes, which involve mixing loose fibers or mechanically crushed fibers with fillers and binder aqueous solutions to make a slurry. The slurry is then poured into a mold equipped with a vacuum filtration device, and the water is removed by vacuum filtration. The disadvantages of the vacuum filtration molding process are: (1) the density of the product is uneven, which affects the product quality; (2) it is easy to remove the tiny particles in the fine powder, which affects the stability of the chemical composition; (3) the moisture content of the molded blank is relatively high, the drying process not only consumes a lot of energy, but also has a large volume shrinkage, the blank is easy to deform, and the subsequent cutting and grinding processing is large; (4) the molding process is relatively complex, which increases the production cost. Therefore, it has become the basic demand of those skilled in the art to propose a preparation method that reduces the amount of materials and energy consumption, and ensures the performance and quality of the product. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention discloses a high-temperature fiber product and its preparation method.

[0004] To achieve the aforementioned objective, the present invention employs the following technical solution:

[0005] A method for preparing a high-temperature fiber product specifically includes the following preparation steps:

[0006] (1) Prepare raw materials:

[0007] The raw materials include mullite crystal fibers with Al2O3 ≥ 80%, fillers, and loss on ignition.

[0008] The fillers are fine alumina powder, fine high-purity mullite powder, and fine high-purity silica powder;

[0009] The material lost on ignition was polyester fiber;

[0010] Mullite crystal fibers with Al2O3 ≥ 80% were machine-cut into two specifications with lengths of 4-5 mm and 2-3 mm, and mixed evenly with each in a 50% mass ratio as raw materials for mullite crystal fibers; polyester fibers were machine-cut into lengths of 2-3 mm as raw materials for polyester fibers.

[0011] The mullite crystal fiber and filler are mixed in the following mass ratio: mullite crystal fiber: filler = 70-75: 25-30;

[0012] The mass ratio of alumina fine powder, high-purity mullite fine powder, and high-purity silica fine powder in the filler is: alumina fine powder : high-purity mullite fine powder : high-purity silica fine powder = 60-65 : 30-35 : 3-5;

[0013] The amount of polyester fiber added to the ignition loss product is 3-5% of the total weight of the mullite crystal fiber and filler;

[0014] (2) Mixing:

[0015] Weigh the above raw materials according to the proportions, mix them evenly in a planetary mixer, and then add a binder to mix into a semi-dry material.

[0016] (3) Molding:

[0017] The semi-dry material is added into the mold, vibrated and pressed to form a blank, and then the blank is demolded and dried.

[0018] (4) Calcination:

[0019] The dried green body is placed in a high-temperature kiln for calcination at a temperature of 1500℃-1600℃ for 4-6 hours.

[0020] The method for preparing the high-temperature fiber product, wherein the polyester fiber is one of nylon fiber, polyester fiber, or acrylic fiber.

[0021] The method for preparing the high-temperature fiber product, wherein the binder is a mixed aqueous solution of dextrin or starch and aluminum dihydrogen phosphate, or a mixed aqueous solution of dextrin or starch and acidic silica sol, and the amount of binder added is 3-5% of the total weight of the raw materials.

[0022] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0023] The method for preparing high-temperature fiber products according to the present invention improves the high-temperature performance of the fiber products by adding high-purity mullite as a filler. A small amount of high-purity silica powder is introduced into the filler. During calcination, the silica reacts with alumina to generate a small amount of mullite, resulting in a slight volume expansion, which reduces the volume shrinkage of the fiber products during calcination. A small amount of polyester fiber is added to reduce the bulk density of the fiber products. Aluminum dihydrogen phosphate and acidic silica sol are both inorganic binders, and their binding force persists from low temperature to high temperature. Dextrin and starch are high-viscosity flexible binders, which can improve the integrity of the fiber material during compression molding and the room temperature strength of the molded blank.

[0024] The method for preparing high-temperature fiber products according to the present invention produces high-temperature fiber products with a bulk density of 0.5-0.8 g / cm³.3 The compressive strength at room temperature ranges from 1.0 to 3.0 MPa, and the operating temperature can reach 1650℃-1700℃. This product can be used as a thermal insulation material or directly as a furnace lining material. It adopts a semi-dry molding process, which is simple, energy-efficient, and has low production costs. Implementation

[0025] The present invention will be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0026] The method for preparing the high-temperature fiber product specifically includes the following preparation steps:

[0027] (1) Prepare raw materials:

[0028] The raw materials include mullite crystal fibers with Al2O3 ≥ 80%, fillers, and loss on ignition.

[0029] The fillers are fine alumina powder, fine high-purity mullite powder, and fine high-purity silica powder;

[0030] The material lost on ignition was polyester fiber;

[0031] Mullite crystal fibers with Al2O3 ≥ 80% were machine-cut into two specifications with lengths of 4-5 mm and 2-3 mm, and mixed evenly with each in a 50% mass ratio as raw materials for mullite crystal fibers; polyester fibers were machine-cut into lengths of 2-3 mm as raw materials for polyester fibers.

[0032] The mullite crystal fiber and filler are mixed in the following mass ratio: mullite crystal fiber: filler = 70-75: 25-30;

[0033] The mass ratio of alumina fine powder, high-purity mullite fine powder, and high-purity silica fine powder in the filler is: alumina fine powder : high-purity mullite fine powder : high-purity silica fine powder = 60-65 : 30-35 : 3-5;

[0034] The amount of polyester fiber added to the ignition loss product is 3-5% of the total weight of the mullite crystal fiber and filler; the polyester fiber is one of nylon fiber, polyester fiber, and acrylic fiber.

[0035] (2) Mixing:

[0036] Weigh the above raw materials according to the formula, mix them evenly in a planetary mixer, and then add a binder to mix into a semi-dry material; the binder is a mixed aqueous solution of dextrin or starch and aluminum dihydrogen phosphate, or a mixed aqueous solution of dextrin or starch and acidic silica sol can be used. The amount of binder added is 3-5% of the total weight of the raw materials.

[0037] (3) Molding:

[0038] The semi-dry material is added into the mold, vibrated and pressed to form a blank, and then the blank is demolded and dried.

[0039] (4) Calcination:

[0040] The dried green body is placed in a high-temperature kiln for calcination at a temperature of 1500℃-1600℃ for 4-6 hours.

[0041] Example 1

[0042] The method for preparing the high-temperature fiber product specifically includes the following preparation steps:

[0043] (1) Prepare raw materials:

[0044] The raw materials include mullite crystal fibers with Al2O3 ≥ 80%, fillers, and loss on ignition.

[0045] The fillers are fine alumina powder, fine high-purity mullite powder, and fine high-purity silica powder;

[0046] The ignition loss was nylon fiber;

[0047] Mullite crystal fibers with Al2O3 ≥ 80% were machine-cut into two specifications with lengths of 4-5 mm and 2-3 mm, and mixed evenly with each in a 50% mass ratio as raw materials for mullite crystal fibers; nylon fibers were machine-cut into lengths of 2-3 mm as raw materials for nylon fibers.

[0048] The mass ratio of mullite crystal fiber to filler is: mullite crystal fiber: filler = 70:30;

[0049] The mass ratio of alumina fine powder, high-purity mullite fine powder, and high-purity silica fine powder in the filler is: alumina fine powder : high-purity mullite fine powder : high-purity silica fine powder = 60 : 35 : 5;

[0050] The amount of nylon fiber added is 5% of the total weight of mullite crystal fiber and filler;

[0051] (2) Mixing:

[0052] Weigh the above raw materials according to the specified ratio, mix them evenly in a planetary mixer, and then add a binder to mix into a semi-dry mixture; the binder is a mixed aqueous solution of dextrin and aluminum dihydrogen phosphate, and the amount of binder added is 5% of the total weight of the raw materials;

[0053] (3) Molding:

[0054] The semi-dry material is added into the mold, vibrated and pressed to form a blank, and then the blank is demolded and dried.

[0055] (4) Calcination:

[0056] The dried billets are placed in a high-temperature kiln for calcination at 1500℃ for 6 hours. Example

[0057] The method for preparing the high-temperature fiber product specifically includes the following preparation steps:

[0058] (1) Prepare raw materials:

[0059] The raw materials include mullite crystal fibers with Al2O3 ≥ 80%, fillers, and loss on ignition.

[0060] The fillers are fine alumina powder, fine high-purity mullite powder, and fine high-purity silica powder;

[0061] The material lost on ignition was polyester fiber;

[0062] Mullite crystal fibers with Al2O3 ≥ 80% were machine-cut into two specifications with lengths of 4-5 mm and 2-3 mm, and mixed evenly with each in a 50% mass ratio as raw materials for mullite crystal fibers; polyester fibers were machine-cut into lengths of 2-3 mm as raw materials for polyester fibers.

[0063] The mass ratio of mullite crystal fiber to filler is: mullite crystal fiber: filler = 75:25;

[0064] The mass ratio of alumina fine powder, high-purity mullite fine powder, and high-purity silica fine powder in the filler is: alumina fine powder : high-purity mullite fine powder : high-purity silica fine powder = 65 : 32 : 3;

[0065] The amount of polyester fiber added is 3% of the total weight of mullite crystal fiber and filler;

[0066] (2) Mixing:

[0067] Weigh the above raw materials according to the specified ratio, mix them evenly in a planetary mixer, and then add a binder to mix into a semi-dry material; the binder is a mixed aqueous solution of starch and aluminum dihydrogen phosphate, and the amount of binder added is 3% of the total weight of the raw materials;

[0068] (3) Molding:

[0069] The semi-dry material is added into the mold, vibrated and pressed to form a blank, and then the blank is demolded and dried.

[0070] (4) Calcination:

[0071] The dried billets are placed in a high-temperature kiln for calcination at 1600℃ for 4 hours. Example

[0072] The method for preparing the high-temperature fiber product specifically includes the following preparation steps:

[0073] (1) Prepare raw materials:

[0074] The raw materials include mullite crystal fibers with Al2O3 ≥ 80%, fillers, and loss on ignition.

[0075] The fillers are fine alumina powder, fine high-purity mullite powder, and fine high-purity silica powder;

[0076] The material lost on ignition was acrylic fiber;

[0077] Mullite crystal fibers with Al2O3 ≥ 80% were machine-cut into two specifications with lengths of 4-5 mm and 2-3 mm, and mixed evenly with each in a 50% mass ratio as raw materials for mullite crystal fibers; acrylic fibers were machine-cut into lengths of 2-3 mm as raw materials for acrylic fibers.

[0078] The mass ratio of mullite crystal fiber to filler is: mullite crystal fiber: filler = 72:28;

[0079] The mass ratio of alumina fine powder, high-purity mullite fine powder and high-purity silica fine powder in the filler is: alumina fine powder : high-purity mullite fine powder : high-purity silica fine powder = 62 : 34 : 4;

[0080] The amount of acrylic fiber added is 4% of the total weight of mullite crystal fiber and filler;

[0081] (2) Mixing:

[0082] Weigh the above raw materials according to the specified ratio, mix them evenly in a planetary mixer, and then add a binder to mix into a semi-dry material; the binder is a mixed aqueous solution of dextrin and acidic silica sol, and the amount of binder added is 4% of the total weight of the raw materials;

[0083] (3) Molding:

[0084] The semi-dry material is added into the mold, vibrated and pressed to form a blank, and then the blank is demolded and dried.

[0085] (4) Calcination:

[0086] The dried billets are placed in a high-temperature kiln for calcination at 1550℃ for 5 hours. Example

[0087] The method for preparing the high-temperature fiber product specifically includes the following preparation steps:

[0088] (1) Prepare raw materials:

[0089] The raw materials include mullite crystal fibers with Al2O3 ≥ 80%, fillers, and loss on ignition.

[0090] The fillers are fine alumina powder, fine high-purity mullite powder, and fine high-purity silica powder;

[0091] The ignition loss was nylon fiber;

[0092] Mullite crystal fibers with Al2O3 ≥ 80% were machine-cut into two specifications with lengths of 4-5 mm and 2-3 mm, and mixed evenly with each in a 50% mass ratio as raw materials for mullite crystal fibers; nylon fibers were machine-cut into lengths of 2-3 mm as raw materials for nylon fibers.

[0093] The mass ratio of mullite crystal fiber to filler is: mullite crystal fiber: filler = 74:26;

[0094] The mass ratio of alumina fine powder, high-purity mullite fine powder, and high-purity silica fine powder in the filler is: alumina fine powder : high-purity mullite fine powder : high-purity silica fine powder = 64 : 32 : 4;

[0095] The amount of nylon fiber added is 4% of the total weight of mullite crystal fiber and filler;

[0096] (2) Mixing:

[0097] Weigh the above raw materials according to the specified ratio, mix them evenly in a planetary mixer, and then add a binder to mix into a semi-dry material; the binder is a mixed aqueous solution of starch and acidic silica sol, and the amount of binder added is 4% of the total weight of the raw materials;

[0098] (3) Molding:

[0099] The semi-dry material is added into the mold, vibrated and pressed to form a blank, and then the blank is demolded and dried.

[0100] (4) Calcination:

[0101] The dried green body is placed in a high-temperature kiln for calcination at a temperature of 1580℃ for 4 hours.

[0102] The high-temperature fiber products prepared by the methods in Examples 1-4 have a bulk density of 0.5-0.8 g / cm³. 3 Between these values, the room temperature pressure resistance is between 1.0 and 3.0 MPa, and the operating temperature reaches 1650℃-1700℃.

[0103] The parts of this invention not described in detail are prior art.

[0104] The embodiments selected herein for the purpose of disclosing the inventive objectives are currently considered suitable; however, it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of this concept and invention.

Claims

1. A method of making a high temperature fiber product, characterized by: Specifically comprising the following Preparation steps: (1) preparing raw materials: the raw materials include mullite crystal fiber with Al2O3≥80%, filler and loss on ignition; the filler is alumina powder, high-purity mullite powder and high-purity silica powder; the loss on ignition is polyester fiber; the mullite crystal fiber with Al2O3≥80% is cut into two specifications with lengths of 4-5 mm and 2-3 mm respectively by a machine, and is mixed uniformly at a mass ratio of 50% each to be used as mullite crystal fiber raw material; the polyester fiber is cut into lengths of 2-3 mm by a machine to be used as polyester fiber raw material; the mass ratio of the mullite crystal fiber to the filler is: mullite crystal fiber: filler = 70-75: 25-30; the mass ratio of the alumina powder, high-purity mullite powder and high-purity silica powder in the filler is: alumina powder: high-purity mullite powder: high-purity silica powder = 60-65: 30-35: 3-5; the addition amount of the loss on ignition polyester fiber is 3-5% of the total weight of the mullite crystal fiber and the filler; (2) mixing: the above raw materials are weighed according to the ratio, mixed uniformly in a planetary mixer, and then a binder is added to mix into semi-dry material; (3) forming: the prepared semi-dry material is added to a mold, and a green body is formed by vibration and pressure molding, and then the green body is demolded and dried; (4) calcining: the dried green body is placed in a high-temperature kiln for calcining, the calcining temperature is 1500-1600℃, and the temperature is maintained for 4-6 hours; The binder is a mixed aqueous solution of dextrin and aluminum dihydrogen phosphate or a mixed aqueous solution of starch and aluminum dihydrogen phosphate or a mixed aqueous solution of dextrin and acid silicon sol or a mixed aqueous solution of starch and acid silicon sol, and the addition amount of the binder is 3-5% of the total weight of the raw materials.

2. The method of making a high temperature fiber article according to claim 1, characterized by: The polyester fiber is one of nylon fiber, polyester fiber and acrylic fiber.